Genelec Measurements

[jjk]

I have a question about the Genelec measurements that Amir makes. Maybe Amir or one of the forum gurus who is familiar with Amir's procedure can answer.
Are the speaker measurements, for instance the recent 8361 post, just done with the analog input to the speaker? Which would mean there is no indication about the performance of the DAC. And what about the performance of the internal amplifier?
Is it just assumed that if the speaker measures well that the amplifier is also top-notch? Should there not be a SINAD measurement for amp and dac?
I am in no way questioning the accuracy of the speaker measurement, just curious about how the amp and dac fit in to the equation.
This question may have been answered elsewhere and if so I apologize. I read many of the Genelec posts but could not find reference for this question.
Thanks to any who can answer. I am considering a Genelec upgrade to my 5.1 system (currently Revel 208/105/205).

 

[nerdoldnerdith]

There is no way to measure those things unless you disassemble the monitor. FWIW, Genelec monitors are free from any audible hiss or noise that would be indicative of lower quality electronics.

 

[HarmonicTHD]

Isn’t the total system performance that what counts and not that of the individual components? This is what was measured.

One does usually not measure the individual drivers and cross-overs of passive speakers either but the total performance (with a few exceptions for reverse engineering or tracking back problems etc).

Personally, I don’t care about the details (but maybe out of some technical curiosity) on how Genelec or others achieve these good results.

 

[DVDdoug]

It's an active speaker so he's using the built-in amplifier. Generally you can't bypass the amp in an active/powered speaker (unless you modify it).

 

[Tom C]

The way these powered monitors often work is that they contain an analog-to-digital converter at the analog input. The difference when using the AES input is that the ADC isn’t needed, so is bypassed. Either way, the internal amps and digital crossovers are utilized. In other words, fear not, the built-in electronics have been tested, and not found lacking.

 

[Tom C]

P.S. You might try a PM to @amirm or post to the review of the unit you are interested in, using his username, to confirm. Please don’t take my word for it. Confirm independently.

 

[dc655321]

Should there not be a SINAD measurement for amp and dac?

No. Unless the electronics are exceptionally poor, their distortion will be swamped by the acoustic distortion. The N in SINAD from the electronics is easily detectable by ear, if sufficiently obnoxious. This is usually mentioned in the active speaker reviews here.

I don’t know if Amir has posted measurements of the amp used during NFS acquisitions of passive speakers. But I also don’t really care, for the reason above.

 

[dfuller]

The way these powered monitors often work is that they contain an analog-to-digital converter at the analog input. The difference when using the AES input is that the ADC isn’t needed, so is bypassed. Either way, the internal amps and digital crossovers are utilized. In other words, fear not, the built-in electronics have been tested, and not found lacking.

Correct.

 

[jjk]

Thanks @TomC. Yes, I might do that but I thought I would try the forum first prior to asking The Man.
I agree with your “confirm independently”.
Again, I am just curious. The review did mention that “you get a dac and an amp for free”.
I was hoping to get objective answers, not opinion.

 

[Sancus]

It would certainly require disassembly, and I don't know if Amir would agree to do that given the potential for damage. Assuming he could even find someone willing to send a monitor in for that purpose(I personally wouldn't).

Anyway, we do know what chip amps are used in the Ones. The spec for the IRS 2092 matches up with the THD listed in the manuals, or 0.01% @ 1khz and 50W. The DAC is probably irrelevant since I'm sure it's bottlenecked by the amplifier. Given the fact that there is some noise, I would *guess* the SINAD of the signal chain is probably 65-75dB. It certainly wouldn't earn any accolades, but would probably get a "fine" like the Crown XLS2502 did, since there is certainly plenty of power(1000W for the 8361A).

In the end, though, it doesn't really matter that much because you can't hook up other electronics to Genelecs. They're an all-in-one system. You either like the performance you see from the speaker measurements, or you don't.

 

[HooStat]

This conversation has happened before. Every time it does, I am reminded that competent DACs sand amps are so far from being the limiting factor in the audio chain.

 

[jjk]

@Sancus, thanks. I will take your word for it.
On the other hand, I would submit that most anyone on this forum who is dropping 10k+ for a pair of 8361s is not going to settle for a Crown or a 65-70 db dac/amp chain.
This is why this question is interesting to me. Not trying to offend anyone, just learn.

 

[jjk]

@HooStat, I don’t understand. Please explain.

 

[Sancus]

@Sancus, thanks. I will take your word for it.
On the other hand, I would submit that most anyone on this forum who is dropping 10k+ for a pair of 8361s is not going to settle for a Crown or a 65-70 db dac/amp chain.
This is why this question is interesting to me. Not trying to offend anyone, just learn.

I think this is a misconception, actually. People on this forum who actually understand the measurements know that >100dB SINADs are unimportant and mostly just a matter of engineering excellence. There can be a certain pride of ownership in owning something that was built so well that it's one of the best performers. It's like somebody who owns a Bugatti Chiron and only drives it on public streets. Are they getting any value out of the theoretical performance? No, but it's not about that.

Frankly, for speakers, and being very generous, anything above 70dB is overkill. Genelec speakers have some of the lowest distortion out there. So, whatever distortion the amps are adding, it's on the order of 1/10 to 1/100th of the drivers themselves.

The amplifier/DAC reviews are different since you're buying them on their own, with no known use. Amir's standard is basically that he is looking to provide a black and white guarantee of audible transparency no matter the use case, which is a much higher standard than "would pass a blind test when used in a particular speaker". That means that, no matter what you use the product for at any point in the future, it will never, ever be a cause of any audible deficiency even if you somehow found yourself with magic 0.001% THD headphones listening in an anechoic chamber.

Incidentally, for DACs in particular, you would want better performance because of headphones which can be much lower thd than speakers. Between the extra noise isolation and the exceptionally low distortion in some high end headphones, it could be argued that you'd want at least 100dB SINAD to be 100% sure it will never be an issue for any future headphone you might buy. Genelec amplifiers are not going to be used that way.

Also, I am specifically the type of person you're talking about. I own 5 Genelec Ones and I bought them like a year after I already knew what the amplifiers in them were. It doesn't bother me at all and I find it pretty puzzling when people are bothered by it. Why would I care about theoretical, inaudible problems?

 

[Pearljam5000]

Why is the THD different between 8361 and 1237/1238?
How significant is it?

 

[Vini darko]

I would expect the measurments to look very funky. Given the active dsp and passive filtering

 

[jjk]

@Sancus
Thanks for clearing up the misconception. I appreciate that.